Migration: person + concept journeys to unified format (#1386)

[CraigBuckmaster]

Summary

Closes #1386 (Phase 2A — Migration for Epic #1379)

One-time migration scripts that convert existing person and concept journey data into the unified journey JSON format.

Scripts created

• _tools/migrate_person_journeys.py — Reads people.json, converts 30 people with journey data → content/meta/journeys/person/*.json
• _tools/migrate_concept_journeys.py — Reads concepts.json, converts 20 concepts with journey_stops → content/meta/journeys/concept/*.json

Output

• 30 person journey files in content/meta/journeys/person/
• 20 concept journey files in content/meta/journeys/concept/
• 50 total journeys, 338 stops, 213 tags loaded into DB

Non-final stops have "bridge_to_next": "[BRIDGE TO AUTHOR]" placeholders — actual bridges authored in #1387 and #1388.

Verification

• schema_validator.py passes (50 journeys, 338 stops validated)
• build_sqlite.py passes (50 journeys, 338 stops, 213 tags in DB)
• validate_sqlite.py passes (90 checks, 0 failures)
• DB confirmed: 30 person + 20 concept journeys

Test plan

• Migration scripts run without error
• Generated files pass schema validation
• Build pipeline loads all 50 journeys
• SQLite validation passes
• CI passes

Note: This PR includes #1385 (save_journey helper) as it's branched from that feature branch.

https://claude.ai/code/session_01Qj6otahNBTSak3fdYhFpes

[github-actions]

Content Pipeline Results

✅ All pipeline checks passed

Step	Status	Details
Schema Validation	✅	134584 passed, 76 failed
Build DB	✅	—
DB Integrity	✅	90 passed, 0 failed

---

Content Pipeline — Quality & Accuracy Report

✅ All content checks passed

Scope: 0 chapter(s) across 0 book(s)

---

Generated by ci_content_check.py

[github-actions]

Test Results

✅ All tests passed

	Passed	Failed	Total
Tests	✅ 3209	❌ 0	3209
Suites	✅ 429	❌ 0	429

Coverage

Statements	Branches	Functions	Lines
—	—	—	—

⏱️ Duration: 79.8s